Intravenous immunoglobulin (VIG) was given by Imbach in 1981 to idiopathic thrombocytopenic purpura (ITP). The cure of many of the patients in response to the IVIG expanded the use of IVIG to other autoimmune condition. The diseases proven the efficacy of VIG by controlled trial were ITP, Guillain-Barré syndrome, chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), multiple motor neuropathy, multiple sclerosis, myasthenia gravis, ANCA related vasculitis, Kawasaki disease, autoimmune uveitis and dermatomyositis. There are several uncontrolled trials and case reports about the efficacy of IVIG on the connective tissue diseases, such as systemic lupus erythematosus, systemic sclerosis, Sjögren syndrome, antiphospholipid antibody syndrome and Still's disease. In Japan, only ITP, Kawasaki disease and CIDP are allowed to be use IVIG by health insurance. I would like to summarize the application of VIG on collagen diseases and refer both novel mechanisms as well as to complications of this therapy.